🧱Debunking the Firewall Vendor Myth | SD-WAN is Not Just "Branch Networking with IPSEC"🐢

In recent years, a growing number of firewall vendors, particularly from Silicon Valley, have tried to rebrand their traditional products as SD-WAN solutions. They often advertise their offerings as being the perfect branch networking tool, wrapped in a cloud-based management interface and powered by IPSEC tunnels for site-to-site connectivity. However, this is a gross oversimplification—and in many ways, a misrepresentation—of what SD-WAN truly is.

By equating SD-WAN with nothing more than branch networking with IPSEC, these firewall vendors miss the mark entirely. In reality, SD-WAN is a far more comprehensive, flexible, and intelligent solution for managing site-to-site connectivity and ensuring optimal network performance. Let's explore what SD-WAN truly is and how the firewall-centric approach falls short in comparison.

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The Real Meaning of SD-WAN

SD-WAN, or Software-Defined Wide Area Network, is a networking technology that fundamentally changes the way businesses approach site-to-site and branch networking. At its core, SD-WAN separates the control plane from the data plane, allowing centralized control and policy-driven traffic management across multiple WAN links. What truly differentiates SD-WAN from traditional networking (or what firewall vendors are peddling as SD-WAN) is its ability to:

1. Dynamically Route Traffic Based on Application Awareness: SD-WAN solutions use real-time metrics such as latency, jitter, packet loss, and throughput to intelligently route traffic across the best available path. Whether it's an MPLS link, broadband, LTE, or even 5G, SD-WAN can dynamically steer traffic based on network conditions to ensure optimal performance. This is far beyond what a simple IPSEC tunnel between branches can achieve.

2. Leverage Multiple Transport Links Simultaneously: True SD-WAN solutions can aggregate and load-balance traffic across multiple WAN links, often using a combination of broadband, MPLS, and cellular connections. This ensures not only redundancy and failover but also enhanced performance by utilizing all available bandwidth. Firewall-centric solutions, by contrast, often rely on a single transport link, usually under the guise of "secure IPSEC tunnels," limiting the potential for performance improvement or redundancy.

3. Provide End-to-End Visibility and Analytics: SD-WAN solutions offer deep visibility into network and application performance, providing real-time monitoring, diagnostics, and analytics across the entire WAN infrastructure. Firewall vendors offering "SD-WAN" tend to limit this visibility to firewall events or security-related logs, which doesn't offer the same level of insight into network health or application performance.

4. Simplify WAN Management and Security with Centralized Orchestration: A key feature of SD-WAN is centralized control via an orchestration platform, where IT teams can apply consistent policies across all branches and optimize network behavior without needing to configure each device manually. While firewall vendors tout their "cloudy GUIs," they are often more focused on firewall rules and VPN setups rather than true orchestration of the entire WAN.

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The Problem with Firewall-Centric Branch Networking Solutions

Firewall vendors from Silicon Valley often confuse or intentionally blur the lines between SD-WAN and traditional firewall-based networking. They argue that because their devices can create IPSEC tunnels between branch offices and have a cloud-based GUI, they qualify as an SD-WAN solution. But here’s why this approach is flawed:

1. Limited Transport Flexibility:

Most firewall vendors’ solutions are optimized for IPSEC-based VPNs. While IPSEC provides encryption, it’s outdated for modern networking needs. These VPN tunnels rely on fixed routing paths, which are rigid and don't adapt dynamically to changing network conditions. True SD-WAN, on the other hand, can flexibly utilize any available WAN transport—broadband, 4G, MPLS, etc.—and switch between them based on real-time performance metrics.

2. Lack of Application-Aware Traffic Steering:

Firewall-centric approaches are built around securing traffic, not optimizing it for performance. This means they lack the advanced traffic management capabilities found in true SD-WAN, where traffic can be prioritized based on application needs. For example, a true SD-WAN solution can prioritize VoIP traffic over file transfers during a network outage, while the firewall-based solution simply encrypts all traffic without any intelligent prioritization.

3. Complexity of Management:

Firewall-based SD-WAN implementations are often complex, requiring manual configuration of tunnels, firewall rules, and routing tables. In contrast, SD-WAN offers centralized policy management that simplifies the entire process. This makes deploying and managing WAN infrastructure much easier, especially at scale, where businesses might have dozens or even hundreds of branches.

4. No Real-Time WAN Optimization:

Firewall vendors’ solutions are limited in their ability to optimize WAN performance. They might secure traffic, but they don't improve it. Real SD-WAN solutions not only provide encryption but also offer features like WAN optimization, traffic shaping, and forward error correction, which help enhance performance, especially over unreliable links like the public Internet.

5. Inconsistent Performance in Hybrid Networks:

Today’s enterprise networks often use a mix of MPLS, broadband, and cellular networks to connect their branches. Firewall vendors’ SD-WAN solutions are typically optimized for single or dual-path connections using IPSEC tunnels. This means they struggle to manage hybrid networks with the same level of efficiency and optimization as a true SD-WAN solution, which can effortlessly handle multiple link types and dynamically route traffic across them.

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Cloud Providers Don’t Use Silicon Valley Firewalls

A fact that often surprises many in the industry is that the major cloud providers, including AWS, Azure, and Google Cloud, do not use firewall vendors' solutions from Silicon Valley for their cloud networking and security. Instead, they rely on Netfilter, the low-level firewall technology built into Linux. Netfilter provides powerful packet filtering, NAT, and stateful tracking capabilities—features that are fully capable of handling enterprise-grade firewall requirements.

The reality is that all cloud-based firewalls are built on Netfilter, not on the proprietary hardware firewalls pushed by Silicon Valley vendors. SD-WAN solutions like Fusion’s SD-WAN leverage Netfilter at the edge to provide advanced firewall capabilities without the additional cost or complexity of third-party appliances.

If a business prefers to use a third-party firewall, Fusion’s SD-WAN also supports NFV (Network Function Virtualization), allowing customers to load an image of any third-party firewall they wish. This provides complete flexibility without locking businesses into a specific vendor’s vision of SD-WAN.

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Wrap | SD-WAN is More Than Just Branch Networking

The interpretation of SD-WAN by firewall vendors as merely branch networking with IPSEC is not only a misunderstanding but also a disservice to the true capabilities of SD-WAN. Real SD-WAN solutions offer far more than encryption tunnels and a cloud-based interface—they provide dynamic routing, multi-link aggregation, traffic optimization, and centralized orchestration.

Firewall vendors' branch networking solutions are inferior to SD-WAN because they lack the intelligence and flexibility required for modern networking. Businesses seeking to enhance their WAN performance should look beyond the firewall vendors’ marketing and choose a true SD-WAN solution that meets the demands of today’s network infrastructure.

Fusion’s SD-WAN, for instance, is a perfect example of how true SD-WAN should function, with its focus on dynamic traffic steering, real-time analytics, and transport agnosticism. It’s time to stop treating SD-WAN as a "cloudy VPN" and recognize it for the robust, intelligent, and future-proof solution it really is.

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Ronald Bartels ensures that Internet inhabiting things are connected reliably online at Fusion Broadband South Africa - the leading specialized SD-WAN provider in South Africa. Learn more about the best SD-WAN in the world: 👉Contact Fusion🚀

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